China's trade surplus widened to $26.7 billion in August compared to the same month last year amid slower-than-expected growth in imports. Exports rose 2.7 percent in August from a year earlier, below the Reuters estimation of 3 percent. But imports surprisingly declined 2.6 percent last month compared with expectations for a 3.5 percent rise. Slower import growth suggests that domestic demand is weaker and bodes ill for the outlook.

The data released Sunday by the National Bureau of Statistics also showed that industrial production in China grew at a slower pace than expected in August. Industrial output rose by 8.9 percent in August in comparison to the same month last year, the weakest reading since May 2009 and also fell short of analysts’ estimate of 9.1 percent growth.

The recent economic reports including last month’s GDP data, which showed that economic activity slowed down in the second quarter, suggest that conditions continue to deteriorate in the world’s second largest economy. However, investors are taking this weakness as an indication of a more decisive policy support.

Economic fundamentals are sluggish but concerns about weak demand from China are outweighed by expectations that bad data would spur further monetary easing and other stimulus steps to bolster growth, supporting commodities generally, Hiroyuki Kikukawa, general manager at trading company Nihon Unicom, told Reuters.

Meanwhile, market participants await the U.S. Federal Reserve's Federal Open Market Committee interest rate decision on Thursday. After the introduction of the new bond-buying program by the ECB, the Fed is widely expected to announce further measures when it closes its two-day meeting.

Japanese shares ended lower, led by declines from blue-chip exporters as weaker-than-expected growth figures weighed. Japanese Gross domestic product (GDP) rose a revised 0.2 percent in April-June on a quarterly basis, down from government's preliminary estimate of 0.3 percent expansion and also below analysts’ estimate of 0.3 percent growth.